Vehicle occupant restraint systems that have an actuatable restraint device are known in the art. The actuatable restraint device of such a system is actuated upon the occurrence of a condition for which a vehicle occupant is to be restrained. An example of a condition for which a vehicle occupant is to be restrained is a vehicle collision.
One type of actuatable restraint system includes an air bag module mounted within a vehicle such that an air bag of the module is inflatable within an occupant compartment of the vehicle. The air bag is inflated upon the occurrence of a condition, such as a vehicle collision. Another type of actuatable restraint system has a seat belt extendable across a vehicle occupant and includes an actuatable device, such as a pretensioner, to move at least a portion of the seat belt relative to the occupant. The pretensioner is actuated upon the occurrence of a condition, e.g., a vehicle collision. The pretensioner removes slack from the seat belt to limit occupant movement.
An actuatable occupant restraint system includes one or more sensors for sensing one or more parameters that are indicative of a condition for which the vehicle occupant is to be restrained. For example, one sensor is a collision sensor, which provides a signal that indicates that the vehicle is in a collision condition. The one or more sensors provide signals to a controller. The controller evaluates the signal(s) and determines whether to actuate the associated occupant restraint.
One type of actuatable restraint system is known as a "smart" type of restraint system. A smart restraint system has one or more adjustable aspects that are adjusted to change the actuation (i.e., deployment) of the restraint device. For example, in a smart restraint system that includes an air bag, the deployment profile of the air bag is adjustable. The adjustable aspects regarding the deployment profile of the air bag may include adjustment of a timing sequence for inflation, adjustment of pressure within the air bag during inflation and upon completion of inflation, and adjustment of air bag position with respect to the occupant.
To make determinations regarding adjustment within a smart restraint system, one or more characteristics of the occupant is/are sensed. For example, one or more sensors of the smart restraint system sense one or more of the following characteristics: size of the occupant, weight of the occupant, and distance between the occupant and a vehicle component surface.